This is ok right?

Kali • Newly married, may 2105. Suffered a natural miscarriage August 2nd, 2015, baby girl due May 2016!
Had an Ultrasound today to make sure my hcg numbers were going up from a new baby, not m/c tissue (I had a natural m/c August 3rd, no period) I think I'm 4 maybe 5 weeks! It's ok to only see gestational sac right? I'm freaking out over nothing right?!